#ifndef RAPIDJSON_WRITER_H_
#define RAPIDJSON_WRITER_H_

#include "rapidjson.h"
#include "internal/stack.h"
#include "internal/strfunc.h"
#include <cstdio>    // snprintf() or _sprintf_s()
#include <new>        // placement new

#ifdef _MSC_VER
#pragma warning(push)
#pragma warning(disable : 4127) // conditional expression is constant
#endif

namespace rapidjson {

//! JSON writer
/*! Writer implements the concept Handler.
    It generates JSON text by events to an output stream.

    User may programmatically calls the functions of a writer to generate JSON text.

    On the other side, a writer can also be passed to objects that generates events, 

    for example Reader::Parse() and Document::Accept().

    \tparam Stream Type of ouptut stream.
    \tparam Encoding Encoding of both source strings and output.
    \implements Handler
*/
template<typename Stream, typename Encoding = UTF8<>, typename Allocator = MemoryPoolAllocator<> >
class Writer {
public:
    typedef typename Encoding::Ch Ch;

    Writer(Stream& stream, Allocator* allocator = 0, size_t levelDepth = kDefaultLevelDepth) : 
        stream_(stream), level_stack_(allocator, levelDepth * sizeof(Level)) {}

    //@name Implementation of Handler
    //@{
    Writer& Null()                    { Prefix(kNullType);   WriteNull();            return *this; }
    Writer& Bool(bool b)            { Prefix(b ? kTrueType : kFalseType); WriteBool(b); return *this; }
    Writer& Int(int i)                { Prefix(kNumberType); WriteInt(i);            return *this; }
    Writer& Uint(unsigned u)        { Prefix(kNumberType); WriteUint(u);        return *this; }
    Writer& Int64(int64_t i64)        { Prefix(kNumberType); WriteInt64(i64);        return *this; }
    Writer& Uint64(uint64_t u64)    { Prefix(kNumberType); WriteUint64(u64);    return *this; }
    Writer& Double(double d)        { Prefix(kNumberType); WriteDouble(d);        return *this; }

    Writer& String(const Ch* str, SizeType length, bool copy = false) {
        (void)copy;
        Prefix(kStringType);
        WriteString(str, length);
        return *this;
    }

    Writer& StartObject() {
        Prefix(kObjectType);
        new (level_stack_.template Push<Level>()) Level(false);
        WriteStartObject();
        return *this;
    }

    Writer& EndObject(SizeType memberCount = 0) {
        (void)memberCount;
        RAPIDJSON_ASSERT(level_stack_.GetSize() >= sizeof(Level));
        RAPIDJSON_ASSERT(!level_stack_.template Top<Level>()->inArray);
        level_stack_.template Pop<Level>(1);
        WriteEndObject();
        return *this;
    }

    Writer& StartArray() {
        Prefix(kArrayType);
        new (level_stack_.template Push<Level>()) Level(true);
        WriteStartArray();
        return *this;
    }

    Writer& EndArray(SizeType elementCount = 0) {
        (void)elementCount;
        RAPIDJSON_ASSERT(level_stack_.GetSize() >= sizeof(Level));
        RAPIDJSON_ASSERT(level_stack_.template Top<Level>()->inArray);
        level_stack_.template Pop<Level>(1);
        WriteEndArray();
        return *this;
    }
    //@}

    //! Simpler but slower overload.
    Writer& String(const Ch* str) { return String(str, internal::StrLen(str)); }

protected:
    //! Information for each nested level
    struct Level {
        Level(bool inArray_) : inArray(inArray_), valueCount(0) {}
        bool inArray;        //!< true if in array, otherwise in object
        size_t valueCount;    //!< number of values in this level
    };

    static const size_t kDefaultLevelDepth = 32;

    void WriteNull()  {
        stream_.Put('n'); stream_.Put('u'); stream_.Put('l'); stream_.Put('l');
    }

    void WriteBool(bool b)  {
        if (b) {
            stream_.Put('t'); stream_.Put('r'); stream_.Put('u'); stream_.Put('e');
        }
        else {
            stream_.Put('f'); stream_.Put('a'); stream_.Put('l'); stream_.Put('s'); stream_.Put('e');
        }
    }

    void WriteInt(int i) {
        if (i < 0) {
            stream_.Put('-');
            i = -i;
        }
        WriteUint((unsigned)i);
    }

    void WriteUint(unsigned u) {
        char buffer[10];
        char *p = buffer;
        do {
            *p++ = (u % 10) + '0';
            u /= 10;
        } while (u > 0);

        do {
            --p;
            stream_.Put(*p);
        } while (p != buffer);
    }

    void WriteInt64(int64_t i64) {
        if (i64 < 0) {
            stream_.Put('-');
            i64 = -i64;
        }
        WriteUint64((uint64_t)i64);
    }

    void WriteUint64(uint64_t u64) {
        char buffer[20];
        char *p = buffer;
        do {
            *p++ = char(u64 % 10) + '0';
            u64 /= 10;
        } while (u64 > 0);

        do {
            --p;
            stream_.Put(*p);
        } while (p != buffer);
    }

    //! \todo Optimization with custom double-to-string converter.
    void WriteDouble(double d) {
        char buffer[100];
#if _MSC_VER
        int ret = sprintf_s(buffer, sizeof(buffer), "%g", d);
#else
        int ret = snprintf(buffer, sizeof(buffer), "%g", d);
#endif
        RAPIDJSON_ASSERT(ret >= 1);
        for (int i = 0; i < ret; i++)
            stream_.Put(buffer[i]);
    }

    void WriteString(const Ch* str, SizeType length)  {
        static const char hexDigits[] = "0123456789ABCDEF";
        static const char escape[256] = {
#define Z16 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
            //0    1    2    3    4    5    6    7    8    9    A    B    C    D    E    F
            'u', 'u', 'u', 'u', 'u', 'u', 'u', 'u', 'b', 't', 'n', 'u', 'f', 'r', 'u', 'u', // 00
            'u', 'u', 'u', 'u', 'u', 'u', 'u', 'u', 'u', 'u', 'u', 'u', 'u', 'u', 'u', 'u', // 10
              0,   0, '"',   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0, // 20
            Z16, Z16,                                                                        // 30~4F
              0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,'\\',   0,   0,   0, // 50
            Z16, Z16, Z16, Z16, Z16, Z16, Z16, Z16, Z16, Z16                                // 60~FF
#undef Z16
        };

        stream_.Put('\"');
        for (const Ch* p = str; p != str + length; ++p) {
            if ((sizeof(Ch) == 1 || *p < 256) && escape[(unsigned char)*p])  {
                stream_.Put('\\');
                stream_.Put(escape[(unsigned char)*p]);
                if (escape[(unsigned char)*p] == 'u') {
                    stream_.Put('0');
                    stream_.Put('0');
                    stream_.Put(hexDigits[(*p) >> 4]);
                    stream_.Put(hexDigits[(*p) & 0xF]);
                }
            }
            else
                stream_.Put(*p);
        }
        stream_.Put('\"');
    }

    void WriteStartObject()    { stream_.Put('{'); }
    void WriteEndObject()    { stream_.Put('}'); }
    void WriteStartArray()    { stream_.Put('['); }
    void WriteEndArray()    { stream_.Put(']'); }

    void Prefix(Type type) {
        (void)type;
        if (level_stack_.GetSize() != 0) { // this value is not at root
            Level* level = level_stack_.template Top<Level>();
            if (level->valueCount > 0) {
                if (level->inArray) 
                    stream_.Put(','); // add comma if it is not the first element in array
                else  // in object
                    stream_.Put((level->valueCount % 2 == 0) ? ',' : ':');
            }
            if (!level->inArray && level->valueCount % 2 == 0)
                RAPIDJSON_ASSERT(type == kStringType);  // if it's in object, then even number should be a name
            level->valueCount++;
        }
        else
            RAPIDJSON_ASSERT(type == kObjectType || type == kArrayType);
    }

    Stream& stream_;
    internal::Stack<Allocator> level_stack_;

private:
    // Prohibit assignment for VC C4512 warning
    Writer& operator=(const Writer& w);
};

} // namespace rapidjson

#ifdef _MSC_VER
#pragma warning(pop)
#endif

#endif // RAPIDJSON_RAPIDJSON_H_
